chain mail vs body armour

chain mail and body armour both are nouns.

Word	Noun	Adjective	Verb	Adverb
chain mail	Yes	No	No	No
body armour	Yes	No	No	No

As nouns, body armour is a hypernym of chain mail; that is, body armour is a word with a broader meaning than chain mail:

Other hypernyms of chain mail include body armor, cataphract, coat of mail, suit of armor, suit of armour.

chain mail (noun)	body armour (noun)
(Middle Ages) flexible armor made of interlinked metal rings	armor that protects the wearer's whole body